In drag racing, the objective is to complete a given straight line distance, from a standing start, ahead of a vehicle in a parallel lane. This distance is traditionally ? mile (400 m), though ? mile (200 m) has become popular since the 1990s. The vehicles may or may not be given the signal to start at the same time, depending on the class of racing. Vehicles range from the everyday car to the purpose built dragster. Speeds and elapsed time differ from class to class. Average street cars cover the ? mile in 12 to 16 seconds, whereas a top fuel dragster takes 4.5 seconds or less, reaching speeds of up to 530 km/h . Drag racing was organized as a sport by Wally Parks in the early 1950s through the NHRA (National Hot Rod Association). The NHRA was formed to discourage street racing.
When launching, a top fuel dragster will accelerate at 3.4 g (33 m/s?), and when braking parachutes are deployed the deceleration is 4 g , more than the Space Shuttle experiences. A top fuel car can be heard over 8 miles (13 km) away and can generate a reading from 1.5 to 3.9 on the Richter scale.
Drag racing is two cars head to head, the winner proceeding to the next round. Professional classes are all first to the finish line wins. Sportsman racing is handicapped (slower car getting a head start) using an index (a lowest e.t. allowed), and cars running under (quicker than) their index break out and lose. The slowest cars, bracket racers, are also handicapped, but rather than an index, they use a dial in.